Without limiting the scope of the invention, its background will be described in relation to an antenna for a vehicle to communicate with a Global Positioning System (“GPS”), Global System for Mobile Communications (“GSM”), and wireless local area network (“WLAN”) systems, as an example.
Wireless communication systems are widely deployed in vehicles to provide various communication services such as voice, data, and so on. These wireless systems may be based on Code Division Multiple Access (“CDMA”), Time Division Multiple Access (“TDMA”), Frequency Division Multiple Access (“FDMA”), or some other multiple-access techniques. A wireless system may implement one or more standards adopted by a standards group or consortium, such as IS-2000, IS-856, IS-95, GSM, Wideband-CDMA (“W-CDMA”), and so on.
A vehicle equipped with wireless communication device(s), such as a cellular or mobile phone, may utilise a transceiver system to obtain two-way communications with a particular wireless system. The transceiver system may include a transmitter for data transmission and a receiver for data reception. On a transmit path, the transmitter may modulate a radio frequency (“RF”) carrier signal with data to produce a RF modulated signal that is more suitable for transmission from the vehicle. Further, the transmitter may condition the RF modulated signal to generate an RF uplink signal and then transmit the RF uplink signal via a wireless channel to one or more base stations in a particular wireless system. On a receive path, the receiver may receive one or more RF downlink signals from one or more base stations, and condition and process the received signal to obtain data sent by the base station(s).
Some vehicles are equipped with a multi-mode wireless device, such as a dual-mode cellular phone, which may be capable of communicating with multiple wireless systems (e.g., GSM and CDMA systems). This capability allows the multi-mode device to receive communication services from more systems and enjoy greater coverage provided by these systems. A multi-mode transceiver may have many signal paths to support all of the frequency bands used by all of the wireless systems. Interconnecting all of these signal paths to the antenna may require a complicated transmitter/receiver (“T/R”) switch with many input/output (“I/O”) RF ports. Additionally, multi-mode wireless system have different and separate antennas for each wireless system it is communicating with, thus creating large and complex arrays of antennas housed together or separately that are not aesthetically pleasing.